The invention relates to a varactor diode comprising a compound semiconductor connector element which has a pn-junction forming a barrier layer or a rectifying metal semiconductor junction (Schottky contact) on one outer face and has an ohmic substrate contact on the outer face of the semiconductor element opposite the barrier layer.
This type of semiconductor arrangement is known for exammple from "1979 IEEE International Solid State Circuits Conference", pages 120 to 121.
For applications on tuners, for example VHF and UHF television tuners, high-quality diodes which vary the capacitance are required having a fixed capacitance characteristic curve over the applied voltage with the posibility of the very great variation in capacitance. In order to achieve high quality, the diode must have a very small series resistance. This series resistance substantially comprises the resistance of the expitaxial layer contained in the semiconductor arrangement and the discharge resistance.
Known gallium arsenide Schottky contacts have a resistance to temperature of approximately 450.degree. C. Consequently, these diodes are cast in plastics or hermetically sealed in ceramic casings.